﻿THE 
  L'ATERITIC 
  FORMATIONS. 
  31 
  

  

  rock 
  is 
  proved 
  by 
  the 
  not 
  unfrequent 
  . 
  occurrence 
  of 
  rounded 
  quartzite 
  

   pebbles 
  imbedded 
  in 
  the 
  solid 
  mass. 
  Other 
  large 
  patches 
  of 
  an 
  identical 
  

   laterite 
  occur 
  at 
  the 
  village 
  of 
  Madaveram 
  (the 
  native 
  name 
  of 
  the 
  

   red 
  Hills) 
  and 
  to 
  the 
  northwest 
  along 
  the 
  banks 
  of 
  the 
  Corteliar 
  

   River, 
  where 
  it 
  is 
  seen 
  capping 
  cliffs 
  of 
  coarse 
  friable 
  brownish 
  grit 
  of 
  

   undeterminable 
  age, 
  provisionally 
  referred 
  to 
  the 
  Cuddalore 
  series. 
  

  

  The 
  appearance 
  of 
  the 
  laterite-spreads 
  at, 
  and 
  north 
  of, 
  the 
  Red 
  

   Hills 
  recalled 
  to 
  mind 
  very 
  vividly 
  the 
  laterite 
  occurring 
  at 
  Vellum 
  

   in 
  the 
  Tanjore 
  District, 
  the 
  uncovered 
  beds 
  presenting 
  on 
  the 
  surface 
  

   the 
  appearance 
  of 
  low 
  reefs 
  of 
  rock 
  on 
  a 
  coast. 
  Between 
  the 
  above 
  

   patches 
  of 
  typical 
  laterite-conglomerate 
  the 
  surface 
  is 
  covered 
  [either 
  by 
  

   lateritic 
  gravel 
  or 
  by 
  the 
  lateritie 
  sands. 
  

  

  On 
  the 
  top 
  of 
  the 
  cliffs, 
  on 
  the 
  right 
  bank 
  of 
  the 
  Corteliar, 
  the 
  

   laterite 
  contains 
  numerous 
  stone-implements, 
  some 
  still 
  imbedded 
  in 
  

   the 
  compact 
  tough 
  rock, 
  others 
  lying 
  loose, 
  having 
  been 
  weathered 
  out. 
  

  

  If 
  we 
  proceed 
  westward 
  from 
  that 
  part 
  of 
  the 
  country, 
  we 
  find 
  a 
  

  

  Increase 
  of 
  coarseness 
  gradual 
  and 
  steady 
  increase 
  in 
  the 
  size 
  of 
  the 
  

   of 
  conglomerates 
  as 
  traced 
  . 
  

  

  to 
  the 
  west. 
  quartzite 
  pebbles 
  in 
  the 
  conglomerate 
  beds 
  till 
  the 
  

  

  source 
  whence 
  they 
  were 
  derived 
  is 
  reached 
  ; 
  and 
  this 
  source 
  is 
  found 
  

   in 
  the 
  enormously 
  coarse 
  conglomerate 
  beds 
  of 
  ' 
  RajmahaF 
  age, 
  sit- 
  

   uated 
  in 
  the 
  Alicoor 
  and 
  Sattavedu 
  hills. 
  

  

  With 
  the 
  increase 
  of 
  coarseness 
  in 
  the 
  conglomerate, 
  the 
  typical 
  

   character 
  of 
  the 
  laterite 
  is 
  lost, 
  for 
  it 
  can 
  no 
  longer 
  be 
  shaped 
  by 
  mere 
  

   cutting 
  into 
  building 
  stones 
  of 
  convenient 
  size, 
  and 
  has 
  lost 
  the 
  singu- 
  

   lar 
  vermicular 
  branching 
  tubes 
  and 
  most 
  of 
  its 
  concretionary 
  structure. 
  

   In 
  extreme 
  cases 
  the 
  ferruginous 
  material 
  forms 
  but 
  a 
  very 
  sparingly 
  

   distributed 
  cement. 
  

  

  South 
  and 
  south-west 
  of 
  the 
  Red 
  Hills 
  tank, 
  typical 
  laterite 
  conglo- 
  

  

  „ 
  , 
  , 
  merate 
  occurs 
  inj 
  patches 
  of 
  different 
  • 
  sizes 
  at 
  

  

  Conglomerates 
  near 
  * 
  r 
  

  

  Avadi. 
  various 
  places, 
  especially 
  to 
  the 
  north 
  of 
  the 
  Avadi 
  

  

  railway 
  station. 
  

  

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  31 
  ) 
  

  

  